PROJECT SUMMARY / ABSTRACT With nearly 116 mln people suffering from chronic pain in the US alone and the global market projected to reach $83 bln by 2024, there is both a major unmet medical need and a significant commercial opportunity. Dominated by opioid drugs, this field also suffered from alarming consequences of opioid drug overuse and misuse. Antagonists acting at TRPV1 receptor have long been recognized as one of the most promising novel classes of non-opioid analgesics. Several drug companies have developed highly selective and potent compounds. Initial tests in humans have confirmed pharmacodynamic profile expected for this class of agents (i.e. analgesia). However, despite an overall good safety and tolerability, there were significant effects on thermoregulation resulting in clinically meaningful hyperthermia and partial loss of heat sensitivity. These effects have led to the discontinuation of essentially all of the advanced programs in the field of TRPV1 antagonists. In this regard, and in line with funding opportunity RFA-DA-19-019, the current application proposes to conduct a set of preclinical proof of concept studies in rats to support the claims that, at doses that have minimal, clinically acceptable or negligible impact on cardiovascular function, a2 adrenoceptor agonists can diminish thermoregulatory effects of TRPV1 receptor antagonists. In Phase 1, we will demonstrate that (Aim 1) presynaptically acting a2 adrenoceptor agonists such as lofexidine can prevent or diminish the hyperthermic responses to TRPV1 receptor antagonists; (Aim 2) at the doses controlling thermoregulatory effects of TRPV1 receptor antagonists, a2 adrenoceptor agonists have minimal or acceptable effects on hypotension.

PROJECT NARRATIVE In an effort to combat overuse and misuse of opioid analgesics, we propose an agent with the different mechanism. Antagonists acting at the TRPV1 receptors have long been recognized as one of the most promising novel classes of non-opioid analgesics but adverse effects on thermoregulation have led to the discontinuation of essentially all of the advanced programs in the field of TRPV1 antagonists. Synventa has discovered a method of controlling the unwanted thermoregulatory effects of TRPV1 antagonists by combining them with centrally acting a2 adrenoceptor agonists. Led by experienced drug hunters, a PI with medicinal chemistry background and a pharmacologist, Synventa proposes to conduct a set of preclinical proof of concept studies to support the claims that, at doses that have minimal, clinically acceptable or negligible impact on cardiovascular function, a2 adrenoceptor agonists can diminish thermoregulatory effects of TRPV1 receptor antagonists.